Hydrocarbon conversion



E. R. KANHOFER HYDROCARBON CONVERSION Filed Aug. 24, 1942 July 1s,1944.v

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' HYDROUMN CONVERSION Elmer-B. Kanhofer, Chicago, Ill.,- assignor toUnivernal O il Products Company, Chicago, Ill., a corporation ofDelaware This invention relates to a process for the conversion ofhydrocarbon oil'into lower boiling hyv drocarbons including gasoline.and more partlcularly to a cracking procs wherein the hydrocarbon oilvmay be converted in two closelyinter- A related steps into a motor fuelof very good antiknock quality and high lead susceptibility.

More specifically, this invention comprises a combination process inwhich hydrocarbon oil the vaporous conversion products into a fraction'containing relatively olenie gasoline boiling rangehydrocarbons and aheavier fraction con-y taining insuiliciently` converted hydrocarbons,

heating and supplying said fraction containing is first treated in aslurry catalyst cracking step l10 and the light and' heavy productstherefrom retreated in a fluidized treating step.

Itisoldinthe artto both in the form of a' slurry and in the form of a.iluidized mass in oil conversion'processes. An-

catalyst cracking and reemploy powdered catalysts relatively olenicgasoline boiling range hydrocarbons Y and heated non-vaporous conversionproducts containing spent catalyst to a secondary conversion zonecontaining a" relatively dense turbulent -mass of powdered catalystwherein they are converted into substantial quantities 'of relativelysaturated motor fuel having good anti- `knock quality and high leadsusceptibility,v sepa.-

rating and recovering said'motor fuel from insufliciently convertedhydrocarbons andreturnother recent development has beenthe process forretreating cracked gasoline in a second' catalytic step to improve theantiknock quality" and lead susceptibility of the motor fuel.. l

In a one stage catalytic' cracking processfthe conditions of operationare usually maintained to produce a highyield of gasoline boiling` rangemaunderstood, reference is made to'the accompanyterial. -Whenthis is thecase, however, a highly Y oleiinic gasollne'is produced. It is'possibleto produce a relatively saturated product in -a single stage whenoperatingl at low temperatures. but

the available charging -stocks suitable for this operation are limited.

In a two step unit a more ilexible operation is obtainable which may beemployed to process a. wide range of charging stocks to produceva veryhigh yield of highly saturated product. The improvement which is'realized in the second or retreating stage of a two step unit is notentirely due to the saturation of the productbut is par- 4tially due tothe rearrangement o f the molecules, that is, the formation of branchedchain compounds' which have a high antiknock quality.

The features o f my invention make it possible to employ existingthermal cracking equipment to produce aviation grade gasoline withonly'a relatively small amount of additional new equipment.

Another feature. of my invention provides for reactivating slurrycatalysts employed in the first 1 step of my process. This isaccomplished in the regenerator of the second step or iiuidizedconversion step. v

In one specic embodiment, my invention comprises heating and supplying ahydrocarbon oil- ....-containing powdered catalyst together withlingsaid lnsuiclently-'converted hydrocarbons to the 'primary conversionzone as hereinbefore set forth.

In order that my invention may be more clearly ingdiagrammatic drawingand the following description thereof. The drawing illustratesschematically in a conventional-side elevation equipment suitable 'foraccomplishing the process of my invention.

Referring to the dr'awing, the rawoilgto be l converted is introduced fothe system through line i; suitable charge pump 2 and valve 8. This `oilmay be diverted all or in part by means of line l '4 and valve I toabsorber l wherein the oil may be employed to scrub catalyst nes fromcombustion gases produced as hereinafter set forth. Part or all of thecharging oil may be diverted around absorber i by means of by-pa'ssglineI and valve In .caseswherein an insuiiiclent quantity of' catalyst is,picked up in absorber 1, additional vcatalyst may be introducedinto theoil in line 1 by 'means which will hereinafter4 be described.

The quantity'of catalyst to be entrained inthe charging oil will bedependent upon the particular charging stock to be converted and willrange heated insufhciently converted hydrocarbons K formed ashereinafter set forth to a primary conl -version zone, separating thenon-vaporous conversion products containing spent catalysts `Vliti fromabout .1 of 1% catalyst by weight of oil up to about 10% by weight ofoil or more depending jupon thel capacity of the oil to form a slurrywith the catalyst.

The charging stock including the entrained catalyst is directed by meansof line 1 through pump ill interposed inline l and valve .i I to heatingcoil l! disposed within heater I3. Within this coil the oil will beheated to a cracking temperature of from about 800 to about 1150 F., -ormore, but preferably within the range oi' from about 90)q to about 1050'and-will normally be maintained at a pressure of from about atmosphericto about 400 pounds per square inch or more. At these conditionsrelatively olefinic gasoline is produced. Coil I2 will normally be of alength to give the oil sufficient time for conversion, but in some casesit may be desirable to include a reaction chamber for additionalcracking time. This reaction chamber, however, is not essentlaltoitheprocess so inorder to simplify the da'wing, it" has not been includedtherein.

'I'he oil after being maintained for a suilcien't time at the desiredtemperature is directed .by means of line I4 through pressure reducingvalve I5 to ilash chamber I6. 'Ioarrest any -further suitable cycloneseparator (or a plurality of sepundesired cracking a suitable 'quenchingoil may be introduced into line I4 by means of line 8| controlled byvalve 62. In this ash chamber, the lighter converted materials will bevaporized and passed overhead throughline I 1 to frac tionator I8v andthe-heavier unvaporized materials containing catalyst will -settle andbe diy verted by means ofline I8 and valve 20 to cooler 2| wherefrom bymeans of line 22 they willbe directed to-receiver 23. A l I Infractionator I8 the -vaporous conversion products from ashchamber-l6will be separated into an overhead cut containing gasolinewhich will be diverted by means of line 24 and valve 25 throughcondenser 26 and line 21 to receiver 28.

` The unliqueed material may be vented from the system atthis point bymeansof line 29 and valve 30. The liquefied portion o f the oil-chargedarators) '50 and line 5I to fractionator 52. In cyclone separator 50,-additional entrained catalyst will be separated from the eilluent streamand be directed by means of line 53 back into the relatively dense zonewithin reactor 41.

In fractionator 52 the converted materials of the desired boiling rangewill pass overhead through line 54. and valve 55 to additionalseparation equipment depending upon the nal boiling range desired. Theheavier and insuilciently l converted materials will be withdrawn fromthe bottom of fractionator 52 by means of line 56 and valve 51 to berecycled to the slurry cracking zone, or this material may be withdrawnfrom the system by means of line 58 and valve 59.

4In Areactor 41 the pressure maintained will preferably b e within, therange of atmospheric to approximately 100 'pounds per square inch toreceiver 28 is withdrawnthrough line 3| and A pump 32 interposed inline3I. A--portion of this material wil1 be returned by means of line-33 and -valve 34 to thetop of fractlonator I8 to serve as a reflux, andthebalance of the'material will be directed by means of line 35 andvalve 36 to line 22 wherein it will be mixed with the unvaporizedmaterial containing catalyst which was separated from the lightermaterials in flash chamber I6. This stream of admixed heavy ma- Aterials, catalyst and lighter overhead materials from fractionator I8isthen directed to receiver 23.

. The'bottom cut from fractionator I8 may be recycled to heating coil I2by means of line 31, valve 38, line 1 and pump I0, or in some cases itmay b'e withdrawn from the system by means ofline 39 and valve 40.

From receiver 23 the commingled heavy. and lighter materials containingcatalyst will be directed by -means of. line 4I, pump 42 interposed inline 4I -and valve 43 to the heating coil 44 located in heater 45. Fromheating coil 44 the oil-will be directed by means of line 46 to reactor41. The temperature of the oil leaving heater will be such that a.temperature within the range of about 750F. to about 1000 F. orpreferably in the range of about 800 to 950 F is maintained in reactor41. Regenerated catalyst is introduced into line 46- as hereinafterdescribed:

Within reactor 41, the mass of catalyst is maintained in a turbulentstate by the action of the uid reactants introduced through line 46. Aperforated distribution plate 48 may be disposed in the lower part ofreactor 41 to 'aid in the *uniform distribution offreactant materialsintroduced thereinto. The catalyst particles in reactor 41 are.maintained in a turbulent state by vthe upward.1iow of reactantmaterials which have a velocity not quite sucient ;to overcome all thegravitationalforces on thecatalyst parand`l therate of oil charged perhourper unit weight of catalyst in the reactor, that is weight spacevelocity, willbe onthe order of approximately .25 to 6, but preferablywithin the range ol .5 to 2. The conditions at which reactor 41ismaintained are such that the olenic gasoline from -the rst step isconverted into a relatively saturated product.

'The catalyst in reactor 41 will becomev contaminated by carbon andhydrocarbonaceous materials andin my process the contaminated catalystmay 'be continuously withdrawn from reactor 41 by means of line 60 andvalve 6I. Flue gases or other inert gases containing a regulatedproportion of oxygen or air is directed throughA line 62 and valve 63and will pick up the contaminated catalyst from line6Il and carry itlinto regenerator 64 wherein the carbonaceous .materials will be burnedfrom the catalyst. The

air introduced through line 62 may be regulated so that the combustion'within regenerator 64 will `be maintained within a temperature range ofapproximately 1000 to 1300 F., but preferably within the range of 1050to 1200 F.

Regenerator 64 will contain a relatively dense.

phase separated by an interface indicated .by dottedl line 88 from alighter phase in the upper portion-cf theregenerator. This upper portion-will actas a settling space forl entrained catalyst particles and theeilluent combustion gases will leave thev regenerator by means of line66 and pass through cyclone separator 61 and line 68 to theaforementioned absorber 6. Catalyst particles entrained in the streampassing .through line 66 will be separated in separator 61 and will bereturned by means of line 69 to the 'dense phase inv regenerator 64.Finelydivided catalyst particles remaining in the effluent gas streamwill be scrubbed therefrom by the vraw oil.charge in absorber 6 and thesubstangases will leave the system tially catalystr free by means ofline and valve 86.

. The regenerated catalyst. particles will be withdrawn from regenerator64 by means of line 1I! and valve 1| and introduced into the heatedreactant stream in line 4l. 'I'he ratio by weight of catalyst: oil inline 46 may be regulated by means of valve 1| and normally will bewithin the range ofv .25 to 25, but preferably will be Within the rangeof 2 to 10. When it is desired to 'include more Ptalys't in the raw oilthan is l picked up in absorber 6, additional catalyst may be withdrawnfrom regenerator 64 by means of line. 12 vcontrolled by valve 13. As isthe case in reactor 41, a perforated plate 65 may be dis` posed in thelower portion of regenerator 64 to aid in the uniform distribution ofincoming materials.

Catalyst make-up may .be introduced 'into the system through line 83 andvalve 84 to line 62. The contaminated catalyst passing through I line 60may be stripped of vaporizable hydrocarbon materials by means of steamor other inert fluids introduced through line 14l and valve 15, and theregenerated catalyst leaving regenerator 64 b'y means of line 10 and 12`may be stripped of air by means of suitable `inert iluidsintroolefln'ic gasoline, separating the resultant conversion productsinto a vapor fraction containing the oleiinie gasoline and a liquidfraction powdered cracking catalyst to a cracking temf' perature for atime period sufiicient to formA containing the powdered catalyst,fractionating l said vapor fraction to separatethe oleflnic gasoline,introducing the olenic gasoline and said fraction containing thepowdered catalyst into Ia zone containing a. bed of powdered crackingcatalyst at a rate such that the bed of catalyst is maintained in astate ofvmotion and therein treating the gasoline fractionunderconditions regulated to produce a substantially olefin-freegasoline while simultaneously separating catalyst from said fraction asthe latter passes in contact with said bed of catalyst.

2. A conversion process whichcomprises subjecting a hydrocarbon oilcontaining suspended powdered cracking catalyst to a crackingternperature for a time period sumcient to form olefinic gasoline,separating thev resultant conversion products into a vapor fractioncontaining the olenic gasoline and a liquid fraction containing thepowdered catalyst, fractionating said vapor fraction to separate theolefin-ic gasoline, combining the oleiinic gasoline with said said bedof catalyst.

fraction containing the powdered catalyst, adding additional catalyst tothe mixture, introducing the resultant mixture into a zone containing' abed of powdered cracking catalyst at la rate such that the bed ofcatalyst ismaintained in a state of motion and therein treating thegasoline. fraction under conditions regulated to produce a substantiallyolen-free gasoline while simultaneously separating catalyst from saidfraction as the latter passes in contact with 3. A conversion-processwhich comprises subjecting a hydrocarbon oil containing suspendedApowdered cracking catalyst to a cracking temperature for a time periodsufcient to form oleiinic gasoline, separating the resultant conversionproducts into a vapor fraction containing the oleflnic gasoline and aliquid fraction containing the powdered catalyst, 'fractionating saidvapor fraction to separate the oleflnic gasoline,

\ combining the oleflnic gasoline with said fraction containing thepowdered catalyst, heating the mixture to a temperature of from about750 to about 1000?l F.,- adding-additional catalyst to lthe thus heatedmixture, introducing the resultant mixture' into a zone containing a bedof powdered cracking catalyst at a rate such that the bed of catalyst ismaintained in a state of motion and'. therein treating' the gasolinefraction under conditions regulated to produce a substantiallyolen-freegasoline while simultaneously separating catalyst from said fraction asthe latter passes ,in contact with said bed of catalyst.

4. `A conversion process which comprises sub- Jecting a hydrocarbon oilcontainingA suspended powdered cracking catalyst to a crackingtemperature for a time period sufiicient to form oleflnic gasoline,separating` the resultant consubstantially olen-free gasoline and toform reversion products into vapor fraction containing the oleflnicgasoline and a liquid fraction containing the powdered catalyst,fractionating saidvapor fraction to separate the oleiinic gasoline,combining the olefinic gasoline with said fraction containing thepowdered catalyst, heating the mixture to a temperature of from about750 to about 1000 F., adding additional catalyst to the thus heatedmixture, introducing the resultant mixture into a zone containing a bedof powdered cracking catalyst at a rate such that? the bed of catalystis maintained in a state of motion and therein treating the gasolinefraction under conditions regulated to produce a substantiallyolefin-free gasoline while simultaneously separating catalyst from saidfraction as vthe latter passes in contact with said bed of catalyst,withdrawing resultant vaporous conversion products from said zone, andseparating entrained catalyst therefrom, fractionating said vaporousconversion products ,to separate the flux condensate and supplying thelatter to the first-mentioned cracking step.

ELMERv R. .KANHOFER.

